This invention relates generally to computer systems and particularly to those characterized as personal computers, and more particularly to those used most frequently by persons having little or no previous experience at programming a digital computer.
Personal computers have become increasingly popular primarily with the advent and availability of low cost processing units such as those utilizing a microprocessor or micro-computer. Such systems vary in structure greatly, but all may be said to contain the common elements of a central processing unit, a keyboard, a display device, and memory associated with the processor. In the majority, if not all, personal computers of the type which the present invention is most advantageous, the central processing unit comprises a microprocessor which has associated with it a memory in which the programming logic of the particular computer language under use is stored together with a sufficient amount of temporary or scratch pad memory in which a processor may temporarily store information to facilitate its processing. The keyboard unit most typically comprises a plurality of alpha-numeric keys generally arranged substantially in accordance with standard typewriter key configurations, but most often including additional keys for switches to facilitate the peculiarities for particular demands of computer programming. The display device most frequently used in present day microprocessor based computers is a cathode ray tube device in which alpha-numeric characters being processed or otherwise related to the programming processed are portrayed on the CRT display screen. In recent years, due largely to cost and convenience factors, many personal computers have been designed for interaction with a convention color television receiver. This, of course, greatly reduces the costs associated with the computer. In such systems, the basic personal computer has included in place of a display device dedicated to the unit a system for modulating the to-be-displayed information upon an available picture carrier in accordance with standard TV broadcast signal construction, whereby the to-be-displayed information is passed to the antenna input for the television receiver.
While a large number of programming languages which facilitate the interaction between the user and the processor of the computer have been devised to suit various needs, the basic process of programming is essentially the presentation of an ordered set of instructions and/or requests to the computer processor by the user which are fashioned in an appropriate language sequence understandable or interpretable by the computer processor and which set up the user's instructions and request to the processor to achieve the end result. By way of simple example, the user may request the computer to solve a particular equation by first stating the equation to the processor, second stating the known values for several of the variable in the equation, and then third request the computer to solve the equation and display the correct number or numbers which correspond to the value of the desired variable.
It is essential, regardless of whether the program being implemented or constructed, is as simple as the foregoing example or much more complex that each instructed presented to the processor be in a form which facilitates the correct communication to the processor. This aspect of programming is one of the most difficult areas for persons having little or only beginner experience with computer programming who desire the right programs for a computer. The majority of errors in information presentation for statement writing, experienced by programmers, are those referred to in the art as errors of syntax and mean in essence a statement has been presented to the computer in a manner which the processor cannot properly interpret. Such syntax errors and the need indeed the insistence of a processor upon a properly syntaxed statement before processing can proceed often result in the appearance of great complicity of operation for the novice and similarly often result in totally frustrating efforts of the beginner and experiencing computer programming.
The problems associated with beginner or novice operation or attempts to program or write programs for a personal computer are of particular concern for manufacturers of low-cost computer devices which with limited resources are designed primarily to be purchased by and used by persons having little or no experience in programming. Recognizing the difficulties of introducing such persons to computer programming and therefore creating consumer acceptance of their product, such manufactures have endeavored to reduce operator complications and frustrations associated with syntax requirements for program writing. For example, many personal computers when confronted with an incorrect statement or command during programming, provide some sort of indication that a syntax error exists in the statement, further some prior art systems in addition provide some indicia of the type of error most often in the form of an error number which permits the operator to consult a look-up table and find the discription of that type of error together with instructions as to how to correct to existing syntax error.
While such systems do provide some help in beginner operation of programmable computers, there remains a need in the art for a simple, easy to use system for communicating the nature and quality of syntax errors to the user. In addition, there remains a need in the art to facilitate the user's interaction with the processor in a manner whereby insignificant errors may be ignored by the processor unit.
Accordingly, it is an object of the present invention to provide a method and structure which facilitates the communication of syntax errors to the user. It is a more particular object of the present invention system to provide a method and structure whereby a maximum of information as to the nature and quality as well as corrective measures for a presented syntax error be communicated to the user without use of external look-up tables and sources of information.